Fig. 



12. 



Fig. 



13. 



Fig. 



14. 



Fig- 



15. 



Fig. 



15a 



Fig. 



16. 



Fig. 



17. 



ORDOVICIAN AND SILURIAN BRACHIOPODA OF THE GIRVAN DISTRICT. 981 



Fig. 3. Ortliis (Hebertella) crista, M'Coy. Brachial valve (from squeeze of impression). x 2. Starfish 

 Bed, Drummuck Group, Thraive Glen. G. 



Fig. 4. Ditto. Internal cast of brachial valve. x 2. Same horizon and locality. G. 



Fig. 5. Ditto. Internal cast of pedicle-valve. x 2. Same horizon and locality. G. 



Fi CT . 6. Ditto. Internal cast of brachial valve, x 2. Same horizon and locality. G. 



Fig. 7. Ditto. Internal cast of pedicle-valve. x 2. Same horizon and locality. G. 



Fig. 8. Orthvs (Hebertella) Lapworthi, Dav. Pedicle-valve.- x 3. Balclatchie Group (conglom.), 

 Balclatchie. G. (Figured, Davidson, Suppl., pi. xiii, fig. 9.) 



Fig. 8a. Ditto. Outline side-view of same specimen. x 3. 



Fig. 9. Ditto. Brachial valve. x 3. Same horizon and locality. G. (Figured, Davidson, ibid., 

 pi. xiii, fig. 10.) 



Fig. 10. Ditto. Pedicle-valve. x 3. Same horizon and locality. G. 



Fig. 10a. Ditto. Outline side-view of same specimen. x 3. 



Fig. 11. Ditto. Pedicle-valve. x 3. Same horizon and locality. G. 

 Ditto, ditto. x 3. Same horizon and locality. G. 

 Ditto. Brachial valve. x 4. Same horizon and locality. G\ 

 Ditto. Internal cast of brachial valve. x 4. Same horizon and locality. G. 

 Ditto ? Pedicle-valve. x 4. Whitehouse Group, Shalloch Mill. G. 



Ditto ? Outline side-view of same specimen. x 4. 

 Ditto ? Brachial valve. x 4. Same horizon and locality. G. 

 Ditto?, ditto, x 4. Same horizon and locality. G. 



Fig. 18. Ortliis aff. Lapworthi, Dav. ? Valve with coarsely fimbriated lamellae, x 4. Same horizon and 

 locality. G. 



Fig. 19. Orthis {Hebertella) scotica, M'Coy. Complete shell, brachial side. x 1^. Stinchar Lime- 

 stone Group, Craighead. S.M. (Figured, M'Coy, Syn. Pal. Foss., pi. i h, fig. 29.) 



Fig. 19a. Ditto. Outline side-view of same specimen. x 1J. 



Fi<*. 20. Ditto. Complete shell, brachial side. x 1£. Same horizon and locality. G. 



Fie. 21. Ditto. Pedicle-valve. x 2. Same horizon and locality. G. 



Fig. 22. Ditto. Side-view of complete shell, x 1J. Same horizon and locality. G. 



Fig. 23. Ditto? Internal cast of brachial valve, x 2. Balclatchie Group, Ardmillan. G. 



Fig. 24. Orthis (Platystrophia) biforata (Schloth.). Pedicle-valve, x 1£. Saugh Hill Group, Wood- 

 land Point. G. 



Fig. 25. Orthis (Platystrophia) dorsata (His.)? Brachial valve of nearly complete shell. Nat. size. 

 Whitehouse Group, Shalloch Mill. G. (Figured, Davidson, Suppl., pi. ix, fig. 26.) 



Fie. 25a. Ditto. Side-view of same specimen, showing small retrorse pedicle-valve. Nat. size. 



Fig. 26. Orthis (Heterorthisl) confinis, Salter. Complete shell (typical form), pedicle-valve. x 1|. 

 Stinchar Limestone Group, Bogang. [4534.] E. 



Fig. 26a. Ditto. Posterior view of same specimen, x \\. 



Fig. 27. Ditto. Internal cast of pedicle-valve, x 1^. Same horizon and locality. [4531a\] E. 



Fie. 28. Ditto. Brachial valve. x 2. Same horizon and locality. [602.] S.M. 



Fig. 29. Ditto. Portion of pedicle-valve, showing ribbing, x 2. Same horizon and locality. [603.] 

 S.M. 



Fig. 30. Ditto? Pedicle-valve, x 1\. Same horizon, .Bennane Burn. G. 



Fig. 31. Orthis (Hebertella) bellatrixl sp. nov. Complete shell. x 1|. Stinchar Limestone Group, 

 Doularg. G. (Labelled by Davidson as "a most characteristic specimen of Orthis confinis, Salt.") 



Fig. 31a. Ditto. Outline side-view of same specimen. x 1£. 



Fig. 32. Orthis (Heterorthis 1) confinis, Salt.? Internal cast of pedicle-valve. xl|. Same horizon. 

 Minuntion. G. 



Fig. 33. Ditto? Internal cast of brachial valve. x lj. Same horizon and locality. G. 



